[adit1329]

Antilock Brake Systems or ABS is a automobile

technology that has been incorporated since 1985

in passenger cars and according to the Fatal

Accident Reporting System, fatal crashes were

reduced by 24 percent, and nonfatal crashes by

14 percent.
However, ABS was introduced as standard

equipment most of the cars during 1991-92 inthe

US.

The fundamental safety problem addressed by ABS

is that drivers are able to optimize the

pressure they apply on the brake pedal, given an

sudden emergency situation or a slippery surface

like a wet road or gravel.

With excessive braking,the wheels lock and the

vehicle can yaw out of the driver's control

(rear-wheel lockup), or go straight ahead,

impossible to steer (front-wheel lockup).

On most road surfaces, a skidding vehicle needs

longer distance to stop than a vehicle with the

brakes applied and wheels still rolling. The

objective of ABS is to take over the

optimization task from the driver. A four-wheel

system is intended to keep all the wheels

rolling during panic braking, to prevent yawing,

to allow steering throughout the emergency and,

on many surfaces, to shorten the stopping

distance.

Multivehicle crashes on wet roads,striking

another vehicle in the rear, or striking a

stopped vehicle is considerably reduced by ABS.

However, studies show dry road crashes are no

way helped by ABS. Also, running off the road,

rollovers are a common ABS problem.

Ideally ABS help prevent lock up. Also, at an

emergency high speed braking, the brake pedal

starts pulsing violently (Experienced this in a

VIVA-Accent). The ideal thing to do is grit your

teeth and brake hard.

In a non ABS car, the ideal way to stop in

emergency is to pump the pedal. In an ABS car do

not do so as this will take longer in an ABS car

to stop.

How does an ABS work? I assume most of us know

and if we do not we can always check it on How

Stuff Works? or the Internet.

The basic principle is that when a wheel is

about to lock up, the speed sensors that is

located in each wheel sends a signal to the

computer and it effectively assigns the correct

pressure to each wheel to conversely affect a

non skid situation.

There are 3 kinds of ABS-
1) Four-channel, four-sensor ABS - this has a

speed sensor on all wheels and the controller

controls each wheel. Most common and ideal

setup.

2) Three-channel, three-sensor ABS - mostly

found on pickup trucks, front wheels have

individual system and the rear has a single

system.

3) One-channel, one-sensor ABS - also found on

trucks, which controls only rear wheels.

**Dates and percentages and sources from

Insurance Institute for Highway Safety**

[vipul_singh]

Sorry for joining the discussion so late, but I think I need to bring out an important point more clearly.

Often, we encounter situations, where not all four wheels are on a similar surface. For instance, the left wheels may be over sand/grit/ice etc., while the wheels on the right hand side may be on asphalt.

In this situation, a hard stop would produce an almost instantaneous pulsation in the brake pedal. Many drivers, would, quite naturally, feel that the wheels are at the limit of their traction, and would either let go of the pressure or, even more likely, hesitate to apply more pressure.

Ideally, one should ignore such 'warning' signs, and increase the pressure as much as possible because you need to maximise the traction available from the 'good' surface (the right hand side, in this case). The car would stop using the traction from the dry side.

Failing to apply the pressure properly in this case, would actually increase the distance over a non-ABS car, as has been correctly suggested here by some of you. Again, the point is to let the computer do the management of the traction. It is upto you to help it do that.

And yes, do not forget to steer!

[Motorholic]

ABS is retrofitted to heavy vehicles like some buses in India. I have seen it myself. Doing it on a car would require an ABS kit first and then mounting of the kit would be the only work left, which might depend from car to car. The company selling them for heavy vehicles dosn't sell it for cars, so procuring a kit would be the first problem.

[sids911]

Hi All,

Taking this thread further...

I am currently in a dilemma of booking a Verna with or without ABS. There would be 20,000 bucks more that I would be spending on it for ABS version. Now the question is, is it really worth spending money on ABS when most of our roads are gravelly?
The NHTSA report http://www-nrd.nhtsa.dot.gov/vrtc/ca...T4FinalRpt.pdf talks about ABS equipped vehicles involving in "run-off-the-road" accidents more that non-ABS equipped vehicles. I figure its the lack of drivers experience with ABS braking and steering while hard braking. Can ppl having cars with ABS share if they face any issues in day-to-day indian traffic?

Seems like airbags are more effective than ABS as a second line of defense after the seatbelts. Pity, the Verna doesnt come with any.

And does anyone know whats the version no. of ABS on Verna and does it come with Traction control and Electronic Brakeforce Distribution?

Siddharth..

[suman]

Originally Posted by sids911

I am currently in a dilemma of booking a Verna with or without ABS. There would be 20,000 bucks more that I would be spending on it for ABS version. Now the question is, is it really worth spending money on ABS when most of our roads are gravelly?

I would always say go for ABS, it helps and will be worth that extra 20k you are plonking down for it; why do you say most of our roads are gravelly, most of them are regular surfaces and there is no possibility of going off the road. I've not had any such issues in the almost 13k mileage that I've covered in my Fiesta SXI (with ABS), in fact, its saved me from a thump on at least a couple of occasions so far. Dirt tracks - well, thats a different matter but how much of that kind of driving would you be doing

Originally Posted by sids911

And does anyone know whats the version no. of ABS on Verna and does it come with Traction control and Electronic Brakeforce Distribution?

Siddharth..

It certainly doesn't have Traction Control though it should have EBD.

[tsk1979]

Well ABS is going to be useful in panic braking situations at medium to high speeds.
Since we have them once a year, it does not make sense to go for ABS.
Accidents are rare too, so forget about airbags too!!?

Indian highwys allow high speed motoring, so if you like riding them, ABS will help you a lot in getting out of tricky situations.

[sumitdongerkery]

Guys Guys!!!!!

Do you mean to say that u can never lock tyres in an ABS equipped car.... I differ to agree here... cos I had locked tyres of Swift ZXi during one of the test runs and also locked the tyres of my octavia once... Infact even I was of the opinion that it is practically not possible to lock the tyres of an ABS equipped car.. but was surprised...

Cheers

[suman]

Originally Posted by sumitdongerkery

Guys Guys!!!!!

Do you mean to say that u can never lock tyres in an ABS equipped car.... I differ to agree here... cos I had locked tyres of Swift ZXi during one of the test runs and also locked the tyres of my octavia once... Infact even I was of the opinion that it is practically not possible to lock the tyres of an ABS equipped car.. but was surprised...

Cheers

Sumit, on a tarmac/concrete surface, IF the ABS kit is a quality product & is functioning properly, there should be no lock ups or squealing. It is quite possible that the Swift demo car may have had issues with its ABS but I'm not sure about your Octavia.

Perhaps you could describe the circumstances under which this happened maybe that would throw some light?

[manavdotcom]

How does one find out wheather ABS is there in a car or not. While buying from used car mkt ?

[Wheeliej]

Originally Posted by GTO

Correction : Not at all times. In dusty road conditions, ABS can actually increase the braking distance.
GTO

dusty road conditions are what you find all over India......

[suman]

Originally Posted by manavdotcom

How does one find out wheather ABS is there in a car or not. While buying from used car mkt ?

When you switch on the ignition, the ABS indicator will light up and then go out...so you know

[adya33]

Originally Posted by tsk

Well ABS is going to be useful in panic braking situations at medium to high speeds.

Not only that but ABS comes in real handy when driving on loose gravel.

Originally Posted by sumitdongerkery

Do you mean to say that u can never lock tyres in an ABS equipped car.... I differ to agree here... cos I had locked tyres of Swift ZXi during one of the test runs and also locked the tyres of my octavia once...

Here note that Swift doesn't have all disk brakes. It has disk breaks only on front tyres.

Originally Posted by manavdotcom

How does one find out wheather ABS is there in a car or not. While buying from used car mkt ?

Like suman said the ABS indicator should come on.
Alternately you can always visit the showroom and ask for clarification. (Eg. If you are buying second hand WagonR visiting Maruti showroom will give you details of various features available for different trims)

[ram_hyundai]

ABS means anti lock braking system-and the popular belief is that a car equipped with ABS stops fast on the contrary its not so and thats mainly becose there is only rolling friction involved and no sliding fricion as the wheels do not lock.but it helps you when the braking situation involves two tyres on tarmarc and two on sand where there is a high possiblity of the tyre on sand getting locked and the car loosing its stablity.

[gonecase_01]

i just wanted to add that paying an extra 20k for something which can save your life in case of instability during an accident is not too much.

[sandeep108]

Just go for ABS. It helps in 95% of the situations. It has saved my Swift ZXI from bumps more than twice and for monsoon it is essential. I am not too sure how anyone can lock up wheels with functioning ABS. It may feel locked up right towards the end, but otherwise, I clearly felt the pedal pulsating and the tire skidding, rolling to gain traction again to help the braking.